DESCRIPTION: The goal of Project I is to study the category abstraction abilities of both autistic individuals and family members of diagnosed autistics. The studies will focus on two domains of knowledge - faces and objects. The studies with faces will explore both the categorization of facial information (gender and expression) and the ability of participants to form prototypical representations and use this information for facial recognition. A related set of studies will focus on the object categories. It is hypothesized that autistics do not form categories in which exemplars differ in typicality and that they do not form prototypic representations of object categories. The investigators will also determine the familiality of these deficits to determine if they can be used as endophenotypic markers. These proposed deficits may be the result of aberrant processes related to the fusiform gyrus, a possibility that will be explored more directly by comparing the results of this project with those of Project II.